The several embodiments of this disclosure relate generally to self-coupling strapping devices that may be referred to as tie straps, cable ties, zip ties, tie wraps, wire ties, and so on, whose many uses may include securing objects in place, bundling objects together, and tying bags closed. Tie straps generally comprise an elongated flexible strap extending from a stout retaining head. Disposed on the strap is usually a plurality of laterally protruding transverse ribs or grooves adapted to couple with a retaining mechanism disposed on or within the head. Common retaining mechanisms include slotted apertures through which the strap may be inserted or pawls under or against which the strap may be positioned.
Many variations exist, for example ribbed flat straps, elastomeric (compressible) straps, beaded filaments, and so on. Generally, at least one rib, bead, barb, ridge, notch, or groove of a tie strap engages with the retaining mechanism. Related strapping devices include: (1) ratchet straps and tie downs whose lateral surfaces are substantially smooth or uninterrupted and which engage with a retaining mechanism by friction, compression, or wrapping; (2) power-cord ties that engage by means of hook-and-loop fasteners (e.g., Velcro); and (3) power-cord ties that engage by means of a protruding button being inserted into a keyhole aperture.
Single-use tie straps have been around for a long time, for example U.S. Pat. No. 588,848, entitled “Bag-fastener,” and more recently U.S. Pat. No. 2,979,794, entitled “Wire or Cable Bundle Tie.” Although such tie straps are useful for many applications, some applications demand reusable tie straps or tie straps that can be arbitrarily tightened and loosened. Consequently, multiple-use tie straps with releasable retaining mechanisms have been developed, for example U.S. Pat. No. 4,991,265, entitled “Cord Tie Device,” and U.S. Pat. No. 5,193,250, entitled “Releasable Cable Tie.” Similarly, releasable retaining mechanisms have been achieved with elastomeric materials, for example U.S. Pat. No. 7,866,005, entitled “Elastomeric Releasable Cable Tie,” and U.S. Pat. No. 8,276,244, also entitled “Elastomeric Releasable Cable Tie,” and U.S. Pat. No. 9,021,665, entitled “Elastic Zip Tie.”
U.S. Pat. No. 9,021,665, entitled “Elastic Zip Tie,” teaches a foam rubber tie strap comprising a strap with a plurality of flexible fin-like ribs on two sides of a body region and only a single retaining aperture in a head region, wherein the head thickness is substantially larger than the longitudinal length of the holding space between adjacent jaws by at least 1.15 times. For such a tie strap to function, it must be made of a sufficiently stretchable material. Further, this tie strap does not include apertures in the body or a catch mechanism adjacent to the head.
German Patent Application DE 2,618,546, entitled “Closure for Hose or Bag-shaped Container,” and French Patent 1,288,123, entitled “Fastener for Bags Made of Soft Material,” teach tie straps for enclosing bag-shaped containers. Each has a pair of slotted apertures in a head region and a plurality of ribs on at least one lateral surface of the body. Neither tie strap includes apertures in the body or a catch mechanism adjacent to the head.
A beneficial aspect of a tie strap is the ability to secure to a first object semi-permanently and to secure to a second object temporarily. This allows the tie strap to stay attached to an object, for example a vertical post, while permitting a second object to be repeatedly secured thereto and removed therefrom, for example a broom handle. In the immediate example, the tie strap may be secured to the post for an extended duration, and the broom may be repeatedly secured thereto and unsecured therefrom while not in use. Similarly, such a tie strap may be used to bundle objects or cords. For example, a tie strap may be wrapped around and secured to several loops of an extension cord when the cord is stowed. When the cord is to be used, the temporary securing means of the tie strap may be disengaged, but the semi-permanent securing means remains engaged so that the tie strap stays attached to the end of the cord.
U.S. Pat. No. 6,317,933, entitled “Binding Band” and U.S. Pat. No. 6,588,074, entitled “Self-mating Reclosable Binding Strap and Fastener,” address semi-permanent and temporary strapping by teaching a tie strap with a slotted aperture in a head region adapted to receive the body, wherein the body includes hook-and-loop (or hook-and-pile) for fastening the body to itself. A disadvantage of hook-and-loop fasteners is the loss of fastening strength due to soiling or wear. Similarly, U.S. Pat. No. 6,523,229, entitled “Cord Keeper Strap,” teaches a strap comprising a slotted aperture in a head region adapted to receive the body and a plurality of keyhole apertures in the body adapted to engage with a protruding button disposed between the head and body. Some disadvantages of button-and-keyhole fasteners include splitting of the strap adjacent to a keyhole, unreliable coupling between the button and a keyhole, and coarse adjustment steps resulting from large separations between adjacent keyholes.